defnitely gels, especially Black Magic though. I've tried using the sprays and I don't like how they spin off onto the paint/bodywork. the gels last longer, easier to apply and look the best.
Meg's High Endurance. Doesn't sling or have that "someone just spooged on my tires" look.
Smells like grapes, too.
Saty away from the GEL kind that u put on with a sponge, it gets all over the side of the car when u start driving, even if u towel it off its bad stuff, stick to the foam stuff always worked for me
Ive used the black magic tire gel for a few car details now, it last a really long time but ive noticed that it picks up road deb re bad and its hard to get off when you want to apply a fresh coat..
I have been using the Black Magic Titanium tire gel lately. http://www.blackmagiccarcare.com/Ti_tireWetGel.htm It is a thick gel, you put on a foam applicator, and rub around the tire. It works great, no over spray, no runs. Put on as much, or as little as you want, depending on the shine you want. I have, also, used it on the cowl, mirrors, and black trim around the windows.